The present invention is directed to attaching a slider to a head suspension. More specifically, the present invention pertains to controlling roll static attitude and pitch static attitude during the attachment process.
FIG. 1 illustrates a hard disk drive design typical in the art. Hard disk drives 100 are common information storage devices consisting essentially of a series of rotatable disks 104 that are accessed by magnetic reading and writing elements. These data transferring elements, commonly known as transducers, are typically carried by and embedded in a slider body 110 that is held in a close relative position over discrete data tracks formed on a disk to permit a read or write operation to be carried out. In order to properly position the transducer with respect to the disk surface, an air bearing surface (ABS) formed on the slider body 110 experiences a fluid air flow that provides sufficient lift force to “fly” the slider 110 (and transducer) above the disk data tracks. The high speed rotation of a magnetic disk 104 generates a stream of air flow or wind along its surface in a direction substantially parallel to the tangential velocity of the disk. The air flow cooperates with the ABS of the slider body 110 which enables the slider to fly above the spinning disk. In effect, the suspended slider 110 is physically separated from the disk surface 104 through this self-actuating air bearing. The ABS of a slider 110 is generally configured on the slider surface facing the rotating disk 104 (see below), and greatly influences its ability to fly over the disk under various conditions.
FIG. 2a illustrates a micro-actuator with a U-shaped ceramic frame configuration 201. The frame 201 is made of, for example, Zirconia. The frame 201 has two arms 202 opposite a base 203. A slider 204 is held by the two arms 202 at the end opposite the base 203. A strip of piezoelectric material 205 is attached to each arm 202. A bonding pad 206 allows the slider 204 to be electronically connected to a controller. FIG. 2b illustrates the micro-actuator as attached to an actuator suspension 207. The micro-actuator can be coupled to a suspension fixture 208. Traces 209, coupled along the suspension 207, apply a voltage to the strips of piezoelectric material 205. These voltages cause the strips 205 to contract and expand, moving the placement of the slider 204. The suspension 207 can be attached to a base plate 210 with a hole 211 for mounting on a pivot. A tooling hole 212 facilitates handling of the suspension during manufacture.
FIG. 3 illustrates a prior art method for coupling a slider 204 to a micro-actuator 201. Two drops of epoxy or adhesive 302 are added to both sides of the slider 202. The slider 202 may then be inserted into the U-shaped micro-actuator. The back surfaces of the slider 202 and the micro-actuator 201 are kept at the same height throughout the curing process.
FIGS. 4a–e illustrate a prior art method for coupling the slider 204 and micro-actuator 201 to the head suspension 207. As shown in FIG. 4a, the micro-actuator 201 and the slider 204 are placed on a fixture 401. As shown in FIG. 4b, an epoxy 402 is applied to the base of the micro-actuator 201. A thin shim 403 is placed on top of the micro-actuator 201 and the slider 204. As shown in FIG. 4c, a suspension fixture 208 of the head suspension is placed atop the thin shim 403 and the epoxy 402. A dimple 404 keeps the suspension fixture 208 a parallel distance from the head suspension 207. A connection plate 405 is added to the slider. As shown in FIG. 4d, an ultraviolet laser 406 is used to cure the epoxy 402. FIG. 4e shows the assembled head suspension 207, micro-actuator 201, and slider 204.
FIG. 5 illustrates in a flowchart an alternate prior art method for coupling the slider 204 and micro-actuator 201 to the head suspension 207. The process starts (Step 510) by loading the suspension 207 onto a loading fixture to keep the suspension in a free condition (Step 520). The location for potting the micro-actuator 201 and the slider 204 is detected by using the center of the pivot hole 211 and the center of the tooling hole 212 as a y-axis and the gold ball bonding pad 206 as the datum (Step 530). The potting epoxy is added to the suspension fixture 208 (Step 540). The slider 204 and the micro-actuator 201 are placed upon the suspension fixture 208 (Step 550). The epoxy is cured by ultraviolet curing (Step 560). The combined suspension 207, micro-actuator 201, and slider 204 are unloaded from the loading fixture (Step 570), ending the process (Step 580).
In the current hard disk drive industry, the pitch static attitude (PSA) and the roll static attitude (RSA) are very important and critical parameters for head flying stability. The ability of the magnetic head to read from and write to the magnetic disk will be affected if the flying is not stable. Large variations in the head flying ability could lead to an undesirable disk crash. This leads to head damage, further negatively affecting disk drive reliability.